Lindblad also expressed enthusiasm for the US-flag coastal ship that is nearing completion at Nichols Brothers Boat Builders in the Seattle area. National Geographic Quest, the first newbuild in the company's history, is on target for its June maiden voyage.

Lindblad said he was 'soundly impressed by the quality of workmanship' and 'proud we were able to build in the United States.'

National Geographic Quest is well-booked and 'virtually sold out' for its maiden season, he added.